This invention relates to a time-division-multiplexed telephone exchanger, and more particularly to a level adjuster for a line connected with the exchanger.
In general, in a telephone exchanger, the line loss becomes heavy when a large number of transit lines are connected. It is therefore desirable to reduce the line loss by the use of a 4-wire switching system. However, when the line loss is reduced excessively, various problems such as singing, echo etc. arise. It is accordingly necessary to insert a level adjuster (pad) into the line and to adjust the line loss of the transit line. Since the pads are installed on the individual outgoing and incoming lines (local transit lines) of the exchanger, they are required in large quantities. Another disadvantage is that, in operating the lines, the change of the adjustment is complicated.